This application is related to and claims priority from Japanese Patent Application No. 2001-78866 filed on Mar. 19, 2001, the content of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a combustor for supplying a combustion heat to a heating heat exchanger (heater core) for heating air blown into a passenger compartment, and other vehicle equipment such as an engine (internal combustion engine) and a catalytic converter.
2. Description of Related Art
In a conventional combustor disclosed in JP-A-2000-234567, when an engine is started in a cool season, combustion gas is supplied from the combustor to an intake side of the engine, thereby directly heating a combustion chamber of the engine and improving starting performance of the engine in the cool season. After the engine is started, the combustor heats hot water to be supplied to a heater core.
On the other hand, in a conventional heating combustor, as disclosed in JP-A-9-133328, a hot water passage, through which hot water flows, is generally provided to cover a combustion gas passage through which combustion gas flows. However, in the combustor, combustion gas and hot water are always heat-exchanged with each other. Because the heat of the combustion gas is always transmitted into the hot water, it is difficult to always supply a sufficient amount of heat to a vehicle equipment such as the engine and the catalytic converter.
In view of the foregoing problems, it is an object of the present invention to provide a combustor for supplying a combustion heat to a heating heat exchanger for heating air blown into a passenger compartment, which can supply a sufficient amount of heat to other vehicle equipment such as an engine and a catalytic converter.
It is an another object of the present invention to provide a control method of the combustor, for improving fuel combustibility of the combustor while sufficient amount of heat can be supplied to the other vehicle equipment.
According to the present invention, in a combustor for supplying a combustion heat to a heating heat exchanger and to other vehicle equipment, fuel is burned using air for combustion introduced from an outside to generate combustion gas, and the combustion gas is heat-exchanged with a thermal medium flowing into the heating heat exchanger. A heat-conduction partition member, through which the heat exchange between the combustion gas and the thermal medium is performed, is disposed for partitioning from each other a combustion gas passage through which the combustion gas from the combustion chamber flows and a thermal medium passage through which the thermal medium flows. Further, a first discharge port from which the combustion gas is supplied to the other vehicle equipment is provided in the combustion gas passage, a non-combustion air introduction port from which air for non-combustion is introduced into the combustion gas passage toward the partition member is provided, and an opening/closing device is disposed for opening and closing the non-combustion air introduction port.
Accordingly, when the air for non-combustion is introduced into the combustion gas passage, the temperature of the combustion gas is decreased in the combustion gas passage, and a temperature difference is decreased between the combustion gas and the thermal medium, thereby restricting the heat-exchange therebetween. Thus, heat of the combustion gas can be restricted from being transmitted into the thermal medium, so a large amount of heat can be supplied to the other vehicle equipment. Here, although the temperature of the combustion gas is decreased, a total gas amount is increased, and a total heat amount thereof is not greatly changed.
Preferably, the non-combustion air introduction port is provided at a side of the heat-conduction partition member so that the air for non-combustion flows along a wall surface of the heat-conduction partition member. Therefore, the air for non-combustion readily flows along the wall surface of the heat-conduction partition member, and functions as an air curtain for interrupting a heat transmission from the combustion gas to the thermal medium. Accordingly, heat of the combustion gas can be prevented from being transmitted into the thermal medium, and a large amount of heat can be sufficiently supplied to the other vehicle equipment.
According to a control method of the combustor, when the air for non-combustion is introduced into the combustion gas passage through the non-combustion air introduction port, air-blowing capacity of an air pump for blowing air for combustion and air for non-combustion is increased, as compared with a case where the non-combustion air introduction port is closed and air is blown by the air pump only for combustion in the combustion chamber. Therefore, fuel combustibility of the combustor can be improved while sufficient amount of heat can be supplied to the other vehicle equipment.